init scheme repo

tortoise/.ccls-cache/@home@geir@code@scheme@tortoise/core.c

@@ -0,0 +1,45 @@
+/* Simple backend for a Logo like tortoise drawer. */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+static const int WIDTH = 10;
+static const int HEIGHT = 10;
+
+static FILE*
+start_gnuplot() {
+  FILE* output;
+  int pipes[2];
+  pid_t pid;
+
+  pipe(pipes);
+  pid = fork();
+
+  if (!pid) {
+    dup2 (pipes[0], STDIN_FILENO);
+    execlp ("gnuplot", NULL);
+    return; /* Not reached. */
+  }
+
+  output = fdopen(pipes[1], "w");
+
+  fprintf (output, "set multiplot\n");
+  fprintf (output, "set parametric\n");
+  fprintf (output, "set xrange [-%d:%d]\n", WIDTH, WIDTH);
+  fprintf (output, "set yrange [-%d:%d]\n", HEIGHT, HEIGHT);
+  fprintf (output, "set size ratio -1\n");
+  fprintf (output, "unset xtics\n");
+  fprintf (output, "unset ytics\n");
+  fflush (output);
+
+  return output;
+ }
+
+static FILE* global_output;
+
+int main(int argc, char *argv[]) {
+  global_output = start_gnuplot();
+
+  return EXIT_SUCCESS;
+}